My-Name-MacBook-Pro:blog myusername$
rails server=> Booting WEBrick
=> Rails 3.0.7 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server Exiting /usr/local/lib/ruby/gems/1.9.1/gems/activeadmin-0.2.2/lib/active_admin/namespace.rb:116:in
find_or_build_resource': Tried to
register Comment as Comment but
already registered to Comment
(ActiveAdmin::ResourceMismatchError)
from
/usr/local/lib/ruby/gems/1.9.1/gems/activeadmin-0.2.2/lib/active_admin/namespace.rb:45:in
register' from
/usr/local/lib/ruby/gems/1.9.1/gems/activeadmin-0.2.2/lib/active_admin.rb:141:in
register' from
/Users/myusername/Projects/RoR/blog/app/admin/comments.rb:1:in
' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:235:in
load' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:235:in
block in load' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:225:in
block in load_dependency' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:596:in
new_constants_in' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:225:in
load_dependency' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:235:in
load' from
/usr/local/lib/ruby/gems/1.9.1/gems/activeadmin-0.2.2/lib/active_admin.rb:185:in
block in load!' from
/usr/local/lib/ruby/gems/1.9.1/gems/activeadmin-0.2.2/lib/active_admin.rb:185:in
each' from
/usr/local/lib/ruby/gems/1.9.1/gems/activeadmin-0.2.2/lib/active_admin.rb:185:in
load!' from
/usr/local/lib/ruby/gems/1.9.1/gems/activeadmin-0.2.2/lib/active_admin.rb:212:in
routes' from
/Users/myusername/Projects/RoR/blog/config/routes.rb:2:in
block in <top (required)>' from
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-3.0.7/lib/action_dispatch/routing/route_set.rb:233:in
instance_exec' from
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-3.0.7/lib/action_dispatch/routing/route_set.rb:233:in
draw' from
/Users/myusername/Projects/RoR/blog/config/routes.rb:1:in
' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:235:in
load' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:235:in
block in load' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:225:in
block in load_dependency' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:596:in
new_constants_in' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:225:in
load_dependency' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:235:in
load' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/application.rb:127:in block in reload_routes!' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/application.rb:127:ineach' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/application.rb:127:in reload_routes!' from
/usr/local/lib/ruby/gems/1.9.1/gems/activeadmin-0.2.2/lib/active_admin.rb:123:in
block in setup' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/callbacks.rb:420:in
_run_prepare_callbacks' from
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-3.0.7/lib/action_dispatch/middleware/callbacks.rb:40:in
initialize' from
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-3.0.7/lib/action_dispatch/middleware/stack.rb:33:in
new' from
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-3.0.7/lib/action_dispatch/middleware/stack.rb:33:in
build' from
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-3.0.7/lib/action_dispatch/middleware/stack.rb:79:in
block in build' from
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-3.0.7/lib/action_dispatch/middleware/stack.rb:79:in
each' from
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-3.0.7/lib/action_dispatch/middleware/stack.rb:79:in
inject' from
/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-3.0.7/lib/action_dispatch/middleware/stack.rb:79:in
build' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/application.rb:162:in app' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/application/finisher.rb:35:in
block in ' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/initializable.rb:25:in instance_exec' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/initializable.rb:25:inrun' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/initializable.rb:50:in block in run_initializers' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/initializable.rb:49:ineach' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/initializable.rb:49:in run_initializers' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/application.rb:134:ininitialize!' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/application.rb:77:in
method_missing' from
/Users/myusername/Projects/RoR/blog/config/environment.rb:5:in
' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:239:in
require' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:239:in
block in require' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:225:in
block in load_dependency' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:596:in
new_constants_in' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:225:in
load_dependency' from
/usr/local/lib/ruby/gems/1.9.1/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:239:in
require' from
/Users/myusername/Projects/RoR/blog/config.ru:3:in
block in <main>' from
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.2.1/lib/rack/builder.rb:46:in
instance_eval' from
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.2.1/lib/rack/builder.rb:46:in
initialize' from
/Users/myusername/Projects/RoR/blog/config.ru:1:in
new' from
/Users/myusername/Projects/RoR/blog/config.ru:1:in
<main>' from
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.2.1/lib/rack/builder.rb:35:in
eval' from
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.2.1/lib/rack/builder.rb:35:in
parse_file' from
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.2.1/lib/rack/server.rb:162:in
app' from
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.2.1/lib/rack/server.rb:248:in
wrapped_app' from
/usr/local/lib/ruby/gems/1.9.1/gems/rack-1.2.1/lib/rack/server.rb:213:in
start' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/commands/server.rb:65:in start' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/commands.rb:30:in
block in ' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/commands.rb:27:in
tap' from
/usr/local/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/commands.rb:27:in
' from
script/rails:6:in require' from
script/rails:6:in'
My-Name-MacBook-Pro:blog myusername$

I had the same problem with version 1.0.0.pre, but thankfully, you can suppress ActiveAdmin comments altogether with a config in active_admin.rb then you don't have to alias your own Comment model anymore as mentioned above.